LOS ANGELES - The first witness in the Phil Spector murder trial testified Thursday that she dated the acclaimed record in the 1990s until one day he held her at gunpoint, struck her twice in the head and demanded that she undress.

"I was terrified," said Dorothy Melvin, a former manager for comedian Joan Rivers.

Melvin is the first of at least four women expected to recount drunken, violent encounters with Spector and a firearm. Prosecutors contend the incidents show a pattern that ended on Feb. 3, 2003, when actress Lana Clarkson, 40, was shot in the mouth at Spector's mansion.

Earlier Thursday, two of Spector's lawyers gave the defense's opening statements, telling jurors that blood and gunshot wound evidence will show Clarkson shot herself and that Spector did not pull the trigger.

Melvin presented a "Dr. Jekyll and Mr. Hyde" view of Spector, saying he could be charming and funny, but when he drank heavily he could "snap" and become a "lunatic."

When she visited Spector at his former home in Pasadena in July 1993, the evening started out "lovely," she said. Spector played the piano, they danced and he showed her rock 'n' roll memorabilia. But, she said, he was also drinking vodka straight out of a tall bottle.

She fell asleep on a couch and woke at dawn to find Spector pointing a revolver at her car outside the house. That started an expletive-laced shouting match, she said.

"He started walking towards me and screaming at me to get back in the house," she said. "I stood my ground. He was pointing the gun at me. Then he took his right hand that was holding the revolver and smacked me in the head. At that point, I knew I was in trouble."

Melvin said Spector then ordered her several times at gunpoint to undress. She only took off her jacket.

He later told her to leave but refused to turn over her purse, which she said contained Rivers' passport and $2,000. He accused her of stealing from him.

Melvin tried to drive off Spector's property but couldn't because his driveway gate was closed. Spector then came toward her with a shotgun, asking why she wasn't gone.

Eventually he opened the gate. She left and called police.

Melvin said that when police confronted Spector, he tried to minimize the incident a lovers' quarrel.

When she got the purse back, she decided not to pursue charges.

"I didn't want it to become a National Enquirer cover," she said.

When Spector lawyer Roger Rosen cross-examined Melvin and she acknowledged that she continued to exchange notes with Spector until shortly after Clarkson was killed.

During the defense opening statement, lawyer Linda Kenney-Baden told jurors that "science will tell you Phil Spector did not shoot Lana Clarkson, did not hold the gun and did not pull the trigger."

She highlighted 10 points - including the trajectory of the shot and blood spatters - that support the contention that Clarkson died from a self-inflicted wound.